Melasma · Pigment Lasers · A Physician's Perspective

Pico or Q-switched for melasma? What one small split-face trial found.

Why this question is personal for me

When I was practising in Taiwan, I had several PicoWay and PicoSure systems in my clinics. For anyone who loves lasers, picosecond devices are a bit like owning a Ferrari and a Lamborghini. Seeing them in the garage just makes you happy. At some point it stops being a purely rational business decision, and I think most people who have owned one would quietly admit that.

But the first laser I ever learned on was a Q-switched Nd:YAG, the MedLite C6, and there is always a place in my heart for it. Over the years, Q-switched systems like the C6, the RevLite C9 and now the Hollywood Spectra have been the lasers I reached for every day. In a busy clinic, they are the workhorses.

My own experience has been that, done well, the results are very similar. That is a clinical impression, though, not evidence. So when a properly randomised trial comparing the two in Asian skin was published this year, I read it closely.

What the trial did

Wu and colleagues, at the Plastic Surgery Hospital of the Chinese Academy of Medical Sciences in Beijing, enrolled 16 Asian women with melasma, Fitzpatrick skin types III and IV, average age 44. Each woman had one side of her face treated with a picosecond laser and the other side with a Q-switched laser. Which side got which was decided by random number table.

• Picosecond side: PicoWay 1064 nm (Candela), a 6 mm zoom pass at 0.5–0.7 J/cm², followed by a fractional pass with the Resolve 1064 handpiece. About 2,000 pulses per session.
• Q-switched side: RevLite SI 1064 nm (Cynosure), an 8 mm pass at 2.0–2.3 J/cm² followed by a 6 mm pass at 2.5–3.0 J/cm². About 2,000 pulses per session.
• Three sessions, four weeks apart, with strict sun protection throughout.
• Two dermatologists, who did not know which side had which laser, scored the melasma from standardised photographs at baseline and at 1, 2, 3 and 6 months after the last session.

All 16 women completed the study.

What it found

Both sides improved clearly, and the two lines move almost together.

Pain was the one measure where the two separated. After the first session, fourteen of the sixteen women rated the Q-switched side as more painful, and only one felt the opposite. Pain was only recorded after that first session, though, not across the whole course.

I would take that part with a grain of salt. In my own practice, patients usually say pico and Q-switched feel quite similar. Comfort depends much more on how the handpiece is moved, the settings and the overall treatment plan than on the pulse duration itself.

The recurrence numbers are worth a second look too. Using the paper's main definition, recurrence at six months was 2 of 16 sides with pico and 3 of 16 with Q-switched. The authors also ran an exploratory check that counted any rise of 20% or more from each side's best score after treatment. By that measure, about half of the sides on both lasers had partly come back by six months. That is not a failure of either laser. It is melasma being melasma.

What it does not prove

The authors are careful about this, and I think it is worth being equally careful.

• "No significant difference" is not the same as "equal". Sixteen patients is a small trial. A modest real difference could have been missed, and the picosecond side was numerically a little better at every time point.
• The two sides did not get identical treatment. The picosecond side also had a fractional pass with the Resolve handpiece. If anything, that setup favours pico.
• The Q-switched laser was a RevLite SI, not a Hollywood Spectra. The trial supports Q-switched 1064 nm as a category. It does not test any one machine against another.
• Only three sessions, one centre's protocol and six months of follow-up. Most melasma care runs longer than that.

The paper also notes that two earlier split-face studies, including one in Korean patients, reported a similar picture for these two lasers at 1064 nm, while some studies using the 755 nm picosecond alexandrite have shown larger gains. Wavelength may matter as much as pulse duration.

If you are a patient

The question most people are really asking is: does it matter which one I get?

This trial did not find a clear difference in results, although it was too small to rule one out, and it matches what I have seen in my own patients over the years. What usually makes the bigger difference is everything around the laser: getting the diagnosis right, sun protection every day, settling irritated skin before treating pigment, and having a maintenance plan, because melasma tends to come back.

At Skin Trek, Q-switched treatment on the Hollywood Spectra is available in Richmond Hill, and PicoWay is available at the Skin Trek Laser Centre in Mississauga. Either can be a good starting point, and the consultation is where we work out which fits your skin and your schedule.

If you run a clinic

So for me it is not really a question of Q-switched versus pico.

If a clinic has the budget, or simply loves lasers, a picosecond system is an easy decision. It opens up other indications, and it is genuinely a pleasure to work with.

If you are a volume clinic and you want something that is not fancy but reliably gets the job done, a good Q-switched Nd:YAG is a very reasonable choice. It is more like a Toyota: not the car you photograph, but the one you trust to start every morning. For melasma, this trial did not detect a meaningful gap in results under its protocols, which matches my own experience, although one small study cannot settle the question.

The machine matters less than the hands, the endpoint and the plan for what comes after.

Common questions

Is a pico laser better than a Q-switched laser for melasma?

In a 2026 randomised split-face trial in Asian women with Fitzpatrick III–IV skin, 1064 nm picosecond and 1064 nm Q-switched Nd:YAG lasers both improved melasma, and no statistically significant difference was found in melasma scores, patient-rated improvement or recurrence. The trial was small and compared specific protocols, so it cannot rule out a meaningful difference.

Does a pico laser hurt less than a Q-switched laser?

In the same trial, pain after the first session averaged 3.1 out of 10 on the picosecond side and 5.3 out of 10 on the Q-switched side, and 14 of 16 patients rated the Q-switched side as more painful. Pain was only measured after the first session, and in practice comfort depends a great deal on technique and treatment settings.

Will melasma come back after laser treatment?

Often, yes. In the trial, recurrence at six months was 2 of 16 sides with picosecond and 3 of 16 with Q-switched by the main definition. An exploratory analysis counting any 20% rise from each side's best score found about half of sides on both lasers had partly come back. Melasma is managed rather than cured, so sun protection and a maintenance plan matter as much as the choice of laser.

Sources

Accurate as of November 2026.